The Detailed E30 R-134a Conversion Thread/DIY

[jeffnhiscars]

What's the best way to get the stock aux fan to run on high with A/C button pressed?
I want the low and high to work as per normal when a/c is not on

You jump the resistor to get it to run high but that may disable the low speed circuit for the temp sensor as well. Ive never known that to kick in so never worried about it. The high speed temp sensor should not be affected.

[digger]

What's the best way to get the stock aux fan to run on high with A/C button pressed?
I want the low and high to work as per normal when a/c is not on

[cory58]

Jeff's spent more time with E30 AC systems than anyone I know, and everything in his response is 100% correct, but....

It is highly unlikely that a rebuilt compressor you just bought would not have 134a compatible seals. Good idea to change out the oil, unless you can verify that it's the same as what was put in your system during the 134a conversion. Were all the o-rings changed during the conversion? If not, you should never go back to that mechanic. The original o-rings are not compatible with 134a and will eventually fail, causing you to chase endless leaks. Getting to some of the o-rings is a PITA, so lots of quickie conversions skip that critical step.

Once you have the new compressor sorted, I would just install it, pull a vacuum on the system to get rid of moisture and check for big leaks, pressure test the system for small leaks, vacuum the system again and then fill with 134a. If the pressures on the gauges look good after the fill and you can get the desired discharge air temp at the vents, then drive the car for a while and see if the AC performance is acceptable.

If the performance is not acceptable or if you have to keep adding 134a too often, then start with the full conversion that Jeff described. Knowing that there are no compressor conversion brackets currently being made for E30s, most people say that switching to a parallel flow condenser makes the biggest difference. Others say that the expansion valve is also critical. My cabrio has almost all original hoses and I only have to add one small can of 134a per year, so it hasn't been worth it to change them all out yet.

Most everything you need to know is in this thread, so download one of the Photobucket fixes for your browser and start reading. Hope you get it figured out. I used to live near you (Hollywood), so I appreciate good AC!

Cory

[jeffnhiscars]

Parts geek should be able to tell you how that compressor is set up. Unfortunately there is much misinformation on this subject. Bmws service bulletin on conversions specs compressors that have r134a compatible seals butnare, in fact, still r12 compressors. They are designed to run at different pressures and you are highly unlikely to get good results from an r12 compressor running 134 just with updated seals.

Get a dedicated r134 compressor (good luck finding a mount kit though) a PF condensor, jump,your resistor, upgrade your fan and get barrier hoses that will contain r134 for more than a season or 2. Anything else will disappoint and have you throwing money at it for years.

If you're"authorized BMW mechanic" doesn't understand this, find an AC guy who does

AMHIK

[Wellington23]

HELP! Need answer ASAP!

We recently took our 1988 E30 to have the system converted from R12 to R134A. We took it to an authorized BMW mechanic in our area. We then bought a remanufactured compressor from Parts Geek and the part came in and says it is filled with 3 oz. of oil. We are doing the rest of the A/C project on our own. My mechanic said that I should empty it out because we won't know if the oil that it in it is mineral like the old ones came with or if it's synthetic. He suggested we empty it out and add 3-4 oz. of PAG 46 synthetic. Any advice? Also, when we took out the old compressor it says R12 on the side of it. The new one doesn't say, but it is exactly the same and it was ordered for a 1988 BMW 325i, so I am assuming it is for an R12 system, since that is the original system on the car. Can I install that new compressor that I ordered or should I be ordering a different compressor now that the system was already converted to R134A? HELP! PLEASE!

[dsphil]

Ac compressors

Surprisingly all 4 of my ac compressors are different. All hoses that connect to the compressor has different fittings. I have 2 86 es, 90 is and 318is. Also the compressor bolts for the bracket also have 2 different sizes.

[jeffnhiscars]

the condensor is thinner than a stock fan or SPAL. Honestly you do not need to remove the radiator to do any of of this.

[digger]

I'll Be changing condenser which I don't think can be done from front without removing a bunch of crap that I don't want. so it's been said removal of radiator allows it to be fitted from within engine bay?

[jeffnhiscars]

Was tossing up whether it's worth getting the spal over spinning the stock one on high.

ultimately I've been told by several people now that the airflow through condenser at low vehicle speeds is a key thing so maximum fan flow seems to be the goal to maximise the performance

Can you get condenser and fan installed by removal of radiator and front grills ? I don't want to pull the whole front end if I can

I was able to work my SPAL through the valance on the 87 cabrio. It was snug but very managable and you dont need to remove the radiator to install it or the condensor. I'm not sure when valances changed so can't advise you beyond that.

Oh...and I got the curved blade fan since I think it pushes more air than the straight blade version

[digger]

Was tossing up whether it's worth getting the spal over spinning the stock one on high.

ultimately I've been told by several people now that the airflow through condenser at low vehicle speeds is a key thing so maximum fan flow seems to be the goal to maximise the performance

Can you get condenser and fan installed by removal of radiator and front grills ? I don't want to pull the whole front end if I can

[jeffnhiscars]

Does stock fan run on low when a/C button is pushed ? Or high ? From memory it's low

The AC kicks it on low but I always have jumped them to run on high since it does help the AC at low speeds. The SPAL is hard wired to run on high only and at that speed makes less noise than a stock fan on low.. Just remember to bump the low speed fuse to match the high (7.5-15IIRC). Note that both high and low wires are .75mm so there's no risk of overload. They just defrayed the fuse to match the design load.

[digger]

Does stock fan run on low when a/C button is pushed ? Or high ? From memory it's low

[jeffnhiscars]

is it worth replacing the aux fan when doing a Nissens PF condenser?

is it a 14" or 16" SPAL pusher required, and how much more air does it move compared to the stock aux?

any specific models that make mounting easy?

My build thread has a detailed Spal installation but the Photobucket pics are gone. Some use the 16" but I think it's too big so went with a 14". IIRC on low it may have slightly less capacity than a stock fan but I run it jumped somots def pushing enough air with not nearly as much noise. In short, a good upgrade.

To mount it I did mod 2 of the 3 brackets. 1 I twisted 90 degrees and one I drilled out the rivet and reversed it. I also bought a SPAL pigtail so the entire assembly is removable without removing the valance.

[digger]

is it worth replacing the aux fan when doing a Nissens PF condenser?

is it a 14" or 16" SPAL pusher required, and how much more air does it move compared to the stock aux?

any specific models that make mounting easy?

[Jims5543]

Just an FYI for you guys that do not want to convert their system. You can use HC-12a which is legally obtained and compatible with R-12. Beats the hell out of flushing a system and converting to a less efficient gas.


"HC-12a, also called ES-12a, OZ-12a, and Hydrocarbon Blend B, is a "drop-in" replacement refrigerant for Freon-12. It is considered nearly non-ozone-depleting. The mixture can be used in refrigeration systems designed for R-12. HC-12a provides better cooling than an R-12 system retrofitted to R-134a, with much greater energy efficiency as well. Unlike R-134a, HC-12a is completely compatible with the hoses and oils used in R-12 systems, making the conversion much easier to accomplish. HC-12a is also patent-free due to its non-synthetic nature."

https://www.amazon.com/Cans-REDTEK-Refrigerant-Ounce-Can/dp/B00E5MOPEG/ref=sr_1_3?ie=UTF8&qid=1507829900&sr=8-3&keywords=HC+12a